Lochinvar Shield SNA285-125 - Manual (Page 65)

65
13
Troubleshooting
(continued)
Table 13E (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Water Heater
Interface
FAULT DESCRIPTION CORRECTIVE ACTION
Fan High
OR
Fan Speed High
(will require a manual
reset once the condition
has been corrected. Press
the RESET button on the
display to reset.)
The actual fan RPM is 30% higher than
what is being called for. • Vent/air intake lengths exceed the maximum allowed
lengths. Refer to Section 2 - General Venting for
proper lengths.
• Check for obstruction or blockage in the vent/air
intake pipes or at terminations.
• Check the wiring connections at the fan and at the
main control board.
• Replace the fan.
• Replace the main control board.
Sensor Open
(will require a manual
reset once the condition
has been corrected. Press
the RESET button on the
display to reset.)
Either the heat exchanger inlet water, heat
exchanger outlet water or tank temperature
sensor has been disconnected.
S1 = Outlet Sensor
S2 = Inlet Sensor
• Check the sensors and their associated wiring.
Repair or replace the sensor or wiring if damaged.
• Measure the resistance of the sensors and compare
the resistance to the tables on page 60 of this
manual.
• Replace the sensor if necessary.
Sensor Shorted
(will require a manual
reset once the condition
has been corrected. Press
the RESET button on the
display to reset.)
Either the heat exchanger inlet water heat
exchanger outlet water or tank temperature
sensor has been shorted.
S1 = Outlet Sensor
S2 = Inlet Sensor
• Check the sensors and their associated wiring.
Repair or replace the sensor or wiring if damaged.
• Measure the resistance of the sensors and compare
the resistance to the tables on page 60 of this
manual.
• Replace the sensor if necessary.
External Limit
Switch
(will retry after 5
minutes. RESET may be
pressed after condition is
corrected.)
An optional remote limit switch is not
making. • Check function of remote devices.
• Check for loose or misplaced jumper if external
limit switch is not installed.
Temp O/Shoot
The flue temperature has exceeded the set
parameters for the water heater. • Inspect the heat exchanger. Reference page 57 of
this manual for the procedure on how to clean the
flue side of the heat exchanger.
• Inspect the flue sensor and associated wiring.
Measure the resistance of the flue sensor and
compare to Table 13C on page 60 of this manual.
Replace the sensor if necessary.
• Verify that the vent/air intake pipes are properly
installed and that there are no obstructions.
• Replace the main control board.
Installation & Service Manual TM